This family is known as "filmy ferns" as the fronds are thin and translucent. The sporangia are placed along the margin of the fronds and are protected either by tubular or two-flapped indusia. These ferns tend to curl up when dry, but quickly revive when moistened.

This family contains the easily recognised "kidney fern".

The Hymenophyllum genus has two-flapped indusia, whereas the Trichomanes genus has a tubular indusia with a wide mouth.

Hymenophyllum demissum

The most common of the filmy ferns.

Hymenophyllum dilatatum

Hymenophyllum ferrugineum

The fronds are densely covered with brown stellate hairs.

Hymenophyllum flabellatum

Hymenophyllum flexuosum

Easily recognised by the broad crinkly wing to the stipe and rachis.

Hymenophyllum scabrum

Recognised by the bristles on the stipe.

Hymenophyllum nephrophyllum

"Kidney Fern"

Was previously known as Trichomanes reniforme.

However it was decided that the indusia were flaps that were urn-shaped rather than tubular with a wide mouth as the other Trichomanes.

This image shows the urcinate (urn-shaped) indusia which covered the developing sporangia.

Trichomanes elongatum

"Bristle fern"

The stalk that bore the sporangia inside the tubular indusia continues to grow after the release of the spores and the fronds develop a bristly look.

Trichomanes venosum

This image clearly shows the tubular indusia that covered the developing sporangia.